Here are a few links I have found to be helpful in sun allergy, utarcaria, or sensitivity. I find it under all these names, but whatever it is called, I can't take the sun without suffering from severe hives.

These are information about exposure levels of the sun.

Http://www.Stormfax.Com/uvtable.Htm

http://www.Cpc.Ncep.Noaa.Gov/products/stra tosphere/uv_index/uvi_map.Gif

this is an article from the us food and drug administration about chemical photosensitivities, photoallergies, photoreactions, phototoxicity, and other info.

Http://www.Fda.Gov/fdac/features/496_sun.H tml

these are places to order sun protective clothing. They cost more than walmart clothing, but do help. However, you still can't remain in the sun indefinitely. When I travel, I wear the clothing, then cover the window with another shirt.

Http://www.Sunprecautions.Com/cgi-bin/sgdy namo.Exe?Htname=_home.Htm

http://www.Sunprotected.Com/index.Asp?Page action=viewcats&category=207

i hope these sites are useful to someone here.

Liza